net: convert sock.sk_refcnt from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Reshetova, Elena
2017-06-30 13:08:01 +03:00
committed by David S. Miller
parent 14afee4b60
commit 41c6d650f6
35 changed files with 70 additions and 69 deletions

View File

@@ -325,7 +325,7 @@ struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be
sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
dif, &udp_table, NULL);
if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
sk = NULL;
return sk;
}
@@ -916,7 +916,7 @@ static void udp_v6_early_demux(struct sk_buff *skb)
else
return;
if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))
if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt))
return;
skb->sk = sk;